A 3-dimensional neutronic- hydraulic code is designed to make calculations on boiling water reactors in static conditions. With its restart facilities it is possible to make core follow-up calculations.

The neutronic part of the code is based on nodal theory with coupling coefficients, the so-called Trilux-method. In the hydraulic part the equations of conservation are solved 1-dimensionally along the flow path with one moderator channel and up to 50 coolant channels.

The test cases included in this package has been run by NEADB on a CRAY-XMP/2800 computer. CPU execution times were 300.5 seconds for 5 steps of the big problem; and 33 seconds for 20 steps of the small problem.